Effects of varying virus-spiking conditions on a virus-removal filter Planova™ 20N in a virus validation study of antibody solutions.
ABSTRACT We aimed to investigate the effect of virus-spiking conditions on the filter performance (flux, flux decay, and parvovirus reduction) of the small virus filter Planova™ 20N. We used three kinds of porcine parvovirus (PPV) stocks: serum, serum-free, and purified. The flux profile with PPV spiking was similar to that without spiking for normal load filtration of about 250-300 L/m(2) . High volume (3 vol %) of serum-free PPV and 1 vol % serum PPV reduced the flux to some extent for high-load filtration (over 10 h, ca., 500 L/m(2) , 5 mg/mL IgG solution). Log reduction value (LRV) of PPV was maintained at a high level (>5) over the filtration volume. Flux for Planova™ 20N was only minimally affected by the use of different virus stocks for spiking. Transmission electron microphotography showed that the distribution of PPV particles captured inside the membrane wall was reached until the -60% thickness of the membrane, showing that the membrane of Planova™ 20N has a thick effective layer for virus removal. These results provided evidence for the robustness of the filter performance of Planova™ 20N, showing that it was not easily affected by virus spiking conditions and that it has a large capacity for high-load conditions.
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ABSTRACT: A protein determination method which involves the binding of Coomassie Brilliant Blue G-250 to protein is described. The binding of the dye to protein causes a shift in the absorption maximum of the dye from 465 to 595 nm, and it is the increase in absorption at 595 nm which is monitored. This assay is very reproducible and rapid with the dye binding process virtually complete in approximately 2 min with good color stability for 1 hr. There is little or no interference from cations such as sodium or potassium nor from carbohydrates such as sucrose. A small amount of color is developed in the presence of strongly alkaline buffering agents, but the assay may be run accurately by the use of proper buffer controls. The only components found to give excessive interfering color in the assay are relatively large amounts of detergents such as sodium dodecyl sulfate, Triton X-100, and commercial glassware detergents. Interference by small amounts of detergent may be eliminated by the use of proper controls.Analytical Biochemistry 06/1976; 72:248-54. · 2.58 Impact Factor